They're very good Simon. I'm quite into knots and those videos were very clear.
I imagine the Event knot would go down well. I was recently shown the Falconer's knot and that would be a good one to do as it seems to be little documented.
I use a Blake's Hitch for my guylines, so that or some variant of midshipman's hitch or adjustable hitch would be useful I think.
Other knots I use, that might be useful demonstrated to others are Fisherman's loop, figure of eight loop, bowline, trucker's hitch. That's all off the top of my head, if I think of more I'll add them.
Edit to add constrictor knot, clove hitch, klemheist knot, fisherman's knot.